It is well known in the art of ignition systems for automotive vehicles to have an ignition coil that produces a magnetic energy upon discharge to create a high voltage spark for initiating combustion in an engine cylinder. Typically, the ignition coil includes primary and secondary windings each wound around a spool and disposed about a magnetic core.
The windings may be progressively wound around the spool. With this winding method, wires are wound in layers at an angle to reduce the number of turns between adjacent wires and thus keep the voltage potential low between two adjacent wires. A problem associated with this type of winding method is wire slippage between wire layers wound around the coil bobbin, which creates a large voltage potential between adjacent wires, resulting in wires shorting together. When wires are wound at an angle, the wires at the surface of the spool can slip and slide axially along the spool due to the tension and force that is in the wires above the surface of the spool. After slippage occurs wires will be wound on top of the slipped wire as the winding continues, resulting in a high wire to wire voltage when the coil is operated. There is a need to decrease wire slippage which is critical to maintain a high quality progressive winding.